Radial staging for reentry compressor



June 13, 1967 P. P. TERRANO 3,324,799

RADIAL STAGING FOR REENTRY COMPRESSOR Filed Aug. 5, 1965 2 Sheets-$heet1 INVENTOR. 814/4 P 72224A/0 m' Mf ATTORNEYS June 13, 1967 P. P. TERRANO3,324,799

RADIAL STAGING FOR REENTRY COMPRESSOR Filed Aug. 5. 1965v 2 Sheets-Sheet2 INVENTOR. P4114. Ewen/v0 ATTORNEYS United States Patent 3 324,799RADIAL STAGING FdR REENTRY COMPRESSOR Paul P. Terrano, Cleveland, Ohio,assignor to TRW Inc, Cleveland, Ohio, a corporation of Ohio Filed Aug.5, 1965, Ser. No. 477,480 3 Claims. (Cl. 103-96) This invention relatesgenerally to reentry compressors and more particularly relates to areentry compressor having a single sided rotor and wherein multiplestaging is accomplished by interconnecting multiple concentric pumpingchannels in series flow relation, the multiple concentric channels beingdisposed in confronting registry with multiple concentric rows of bladeshavin an optimum number of blades and a predetermined diameter ratio.

Multiple staging of reentry compressors is frequently desirable asincreased pressures may be required for particular applications. Inaccordance with the principles of the present invention, two or morestages can be obtained in a single sided rotor by disposing multipleconcentric rows of blades and pumping passages in spaced relationrelative to rotational axis. With such an arrangement, the inlet andoutlet ports may be interchanged and the basic arrangement can either berepeated or combined in series or in parallel. Such a multistagingarrangement avoids most of the flow losses inherent in other designs andmore nearly maintains the continuity of fluid flow from the inlet to theoutlet.

It is an object of the present invention, therefore, to provide a meansof multistagin" a reentry compressor of the type utilizing a singlesided rotor.

Another object of the present invention is to provide a multistagingarrangement for a reentry compressor wherein the inlet and outlet portsmay be selectively interchanged with no change in the basic principle.

Another object of the present invention is to provide a multistagingarrangement for a reentry compressor which can be repeated and combinedin series or parallel.

A still further object of the present invention is to provide amultistaging arrangement for a reentry compressor wherein flow lossesare minimized and wherein the continuity of fluid flow from the inletand outlet is preserved.

Many other objects, features, advantages and additional objects of thepresent invention will become manifest to those versed in the art uponmaking reference to the detailed description which follows and theaccompanying sheets of drawings in which an exemplary form of a reentrycompressor is shown by way of illustrative example.

On the drawings.

FIGURE 1 is an elevational view with parts broken away and shown incross-section illustrating an exemplary form of a reentry compressorembodying the principles of the present invention;

FIGURE 2 is a fragmentary cross-sectional view similar to FIGURE 1 butshowing a covered interconnecting passageway between stages;

FIGURE 3 is a cross-sectional view taken generally n the plane of lineIIIIII of FIGURE 2 and illustrates additional details of construction ofthe covering plate;

FIGURE 4 is an elevational view showing additional details ofconstruction of the rotor; and

FIGURE 5 is an elevational view of the cover member provided inaccordance with the principles of the present invention and showing atline II the plane of the crosssectional portions of FIGURE 1.

As shown on the drawings:

Fluid pumps which are commonly known as drag pumps. offercharacteristics in a centrifugal compressor which fall somewhere betweenthose of the positive displacement pump and the centrifugal pump. Thismeans the single stage pump produces a medium pressure at the outputwhen running at a medium speed, as compared with either of the other twotypes. Because of those characteristics and the fact that it is not apositive displacement pump, there are many applications where such apump should do a good job and be economically feasible as compared tothe other two types.

In some instances, it is desirable to have a discharge pressure in thesame magnitude as the positive displacement pump while running in thesame speed magnitude. In accordance with the principles of the presentinvention, such objective can be accomplished by placing additionalstages on the drag pump without increasing the size and complexity ofthe pump by providing multiple concentric rows of blades and pumpingpassages which are interconnected or interrelated to afford amultistaging arrangement.

The pump of the present invention is shown generally at 10 and comprisesa casing 11 having a flange 12 in which is formed a plurality ofthreaded apertures 13. A cover 14, similarly flanged as at 16, passes aplurality of fasteners 17 which together with lock washers 18 may beused to fasten the casing 11 and the cover 14 in firm assembly with oneanother.

The cover 14 is particularly characterized by an inner face 20 havingformed therein a semi-toroidal circumferentially extending pumping duct21 having an inner wall 22 and an outer wall 23, both of which arearranged in generally concentric relation to the axis of the pump,thereby to form a pumping duct which extends circumferentially from anend portion 24 to an end portion 26.

In accordance with the principles of the present invention, a secondpumping duct is shown at 27 and is likewise of semi-toroidalconfiguration extending circumferential-1y and having an inner wall 28and an outer wall 29 and extending from a portion shown at 30 to an endportion 31. The pumping channel or duct 21 is interconnected with thepumping channel or duct 27 by means of a passageway 32.

In the form of the invention illustrated, the cover 14 has a boss 33 inwhich is formed an inlet port 34 communicating with the inner pumpingduct 27 near the end portion 31 thereof.

The cover 14 is further characterized by a boss 36 in which is formed anoutlet port 37, which outlet port 37 intersects the outer pumpingchannel or duct 21 near the end portion 24 thereof. Accordingly, fluidentering the inlet port 31 will pass through the pumping channel or duct27 and thence through the interconnecting passage 32 into the endportion 26 of the outer pumping channel or duct 21 and will then passthrough the outlet port 37.

Referring now to FIGURES 1 and 4, it may be noted that a rotor isprovided at 36 and includes a shaft 37 which is journaled in a bearingassembly shown in dotted outline generally at 38. The rotor 36 has aradial face 39 which is particularly characterized by having formedtherein semi-toroidal circumferentially continuous vane ducts which areconcentric with respect to one another and which are spaced to lie inconfronting registry with the pumping channels or ducts 21 and 27. Inthis connection, note that the face 39 has an outer circumferentiallyextending recess formed therein which is identified at 40 including aninner wall 41 and an outer wall 42.

There is further provided an annular circumferentially extending recess43 having an outer wall 44 and an inner Wall 46.

In the course of fabrication, the rotor 36 is provided with a pluralityof slots which extend transversely of the corresponding recesses 40 and43 and which slots are more specifically identified in FIGURE 4 at 47.Received within each slot 47 is a vane 48 for the outer recess or vaneduct 40 and 49 for the inner recess or vane duct 43. Thus, a pluralityof vanes 48 are disposed in an annular row in circumferentially spacedrelation so that all of the vanes 48 and 49, in the respective recesses40 and 43, form a plurality of impeller pockets 50 and 51 adapted to bemoved upon rotation of the impeller 36 within the casing formed by thecover 14 and the casing 11.

As will be noted upon inspecting the structure shown in the drawings,the two concentric rows of blades 48 and 49 have an optimum number ofblades and an appropriate diameter ratio. In the arrangement shown, theinlet port 34 is near the center and the outlet port 37 is near theoutside diameter, however, it will be readily recognized by those versedin the art that the inlet and outlet ports may be interchanged with nochange in the basic principle. An inlet at the outer diameter isdesirable for certain combinations of flow, pressure and speed, while aninlet at the center is indicated for certain other combinations.Further, the basic arrangement of multiple concentric channels and bladerows can be repeated and can be combined either in series or inparallel. Further, three or more concentric channels could also be usedrather than two, as shown in the exemplary structure, and it will bereadily recognized that if desired, partial channels'could be usedinstead of circumferentially continuous channels.

Further, although in FIGURE the interconnecting passage 32 is shownuncovered, it is also possible to provide a cover for such passage inorder to cut down losses and in this regard a cover is shown in thearrangement of FIGURES 2 and 3 wherein like parts are designated by likenumbers but with a suffix a. As shown in FIG- URES 2 and 3, the areaadjacent the interconnecting passage 32a is recessed at its edges,thereby to receive and seat a sheet metal cover 60 having a narrow end61 located adjacent the end portion a of the inner duct 27a to an endportion 62 which extends transversely as at 63 to overlie the endportion 26a at the end of the outer pumping duct 21a. The recess portionadjacent the edges of the interconnecting passage 32a are shown at 64.

By virtue of the provision made, continuity of fluid flow from the inletport 34 to the outlet port 37 is afforded and multistaging isaccomplished with a minimum of flow loss.

The number of blades, the diameter ratio and the cant angle may bedifierent in each row of blades, depending on performance criteria. Insuch event, the blades may be assembled to the rotor by means other thanthe slotting procedure described by way of exemplification.

It may also be noted that it is desirable that the inlet port be locatednear the inner diameter of the corresponding channel while the outletport should be located near the outer wall of the corresponding channel.

Although minor modifications might be suggested by those versed in theart, it should be understood that I wish to embody within the scope ofthe patent warranted hereon all such modifications as reasonably andproperly come within the scope of my contribution to the art.

I claim as my invention:

1. A fluid pump of the drag type comprising a casing having an inletopening for connection to a source of fluid to be pumped and an outletopening for direction of the pumped fluid to a point of utilization,

said casing having a radial face formed internally thereof characterizedby having formed therein inner and outer concentrically disposed annularpumping ducts communicating with said inlet and outlet ports, a rotor insaid casing having a drive shaft connected thereto,

said rotor having a radial face including annular recesses disposed inconcentric relation for registry with said pumping ducts,

said rotor having a plurality of circumferentially spaced slots eachextending across said annular recesses,

and vane means in said slots to form with said recesses a plurality ofimpeller pockets in each respective recess,

and interconnecting passage means in said casing disposed between saidpumping ducts to interconnect said pumping ducts in staged flowrelation, said radial face of said casing being recessed adjacent saidinterconnecting passage means, and a thin cover member received andseated in said recessed portion of said casing face to overlie saidinterconnecting passage means and the adjacent end portions of saidinner and outer ducts, thereby to insure continuity of fluid flow withminimum flow loss.

2. A reentry compressor comprising a single sided rotor having multipleconcentric rows of blades,

a casing having a wall extending closely adjacent said rotor and havingformed therein multiple concentric pumping channels confronting saidrows of blades,

said wall having passage means formed therein extending radially andinterconnecting said concentric pumping channels in flow relation,

and interchangeable inlet and outlet ports formed in said casingcommunicating with said respective ends of said concentric pumpingchannels to direct pumping fluid to and from the pump, and

means forming a cover for said passage means to reduce flow lossesbetween the concentric pumping channels.

3. A two stage pump comprising a rotor having a radial face,

two concentric blade channels of substantially semi-toroidalcross-section in said face,

a plurality of circumferentially spaced pumping blades in said channelforming a plurality of pumping pockets,

and a casing having two concentric pumping ducts of substantiallysemi-toroidal cross-section confronting said pumping blades,

one end of each of said concentric pumping ducts having a port formedtherein comprising respectively an inlet and an outlet for the pump,

the opposite end of each said concentric pumping ducts beinginterconnected by a crossover passageway to stage said pumping ducts ininterconnected flow relation, and

a cover for said crossover passageway and overlying the adjacent ends ofsaid pumping ducts to reduce flow losses between the pumping ducts.

References Cited UNITED STATES PATENTS 1,635,846 7/1927 Holmes 1031 101,811,651 6/1931 Schlachter 10396 2,256,741 9/1941 Gurley 103963,139,232 6/1964 Peterson 230-131 FOREIGN PATENTS 731,085 2/ 1943Germany.

752,398 10/ 1952 Germany.

874,503 4/ 1953 Germany.

DONLEY I. STOCKING, Primary Examiner.

HENRY F. RADUAZO, Examiner.

1. A FLUID PUMP OF THE DRAG TYPE COMPRISING A CASING HAVING AN INLETOPENING FOR CONNECTION TO A SOURCE OF FLUID TO BE PUMPED AND AN OUTLETOPENING FOR DIRECTION OF THE PUMPED FLUID TO A POINT OF UTILIZATION,SAID CASING HAVING A RADIAL FACE FORMED INTERNALLY THEREOF CHARACTERIZEDBY HAVING FORMED THEREIN INNER AND OUTER CONCENTRICALLY DISPOSED ANNULARPUMPING DUCTS COMMUNICATING WITH SAID INLET AND OUTLET PORTS, A ROTOR INSAID CASING HAVING A DRIVE SHAFT CONNECTED THERETO, SAID ROTOR HAVING ARADIAL FACE INCLUDING ANNULAR RECESSES DISPOSED IN CONCENTRIC RELATIONFOR REGISTRY WITH SAID PUMPING DUCTS, SAID ROTOR HAVING A PLURALITY OFCIRCUMFERENTIALLY SPACED SLOTS EACH EXTENDING ACROSS SAID ANNULARRECESSES, AND VANE MEANS IN SAID SLOTS TO FORM WITH SAID RECESSES APLURALITY OF IMPELLER POCKETS IN EACH RESPECTIVE RECESS, ANDINTERCONNECTING PASSAGE MEANS IN SAID CASING DISPOSED BETWEEN SAIDPUMPING DUCTS TO INTERCONNECT SAID PUMPING DUCTS IN STAGE FLOW RELATION,SAID RADIAL FACE OF SAID CASING BEING RECESSED ADJACENT SAIDINTERCONNECTING PASSAGE MEANS, AND A THIN COVER MEMBER RECEIVED ANDSEATED IN SAID INTERCONNECTING OF SAID CASING FACE TO OVERLIE SAIDINTERCONNECTING PASSAGE MEANS AND THE ADJACENT END PORTIONS OF SAIDINNER AND OUTER DUCTS, THEREBY TO INSURE CONTINUITY OF FLUID FLOW WITHMINIMUM FLOW LOSS.